hopefully this is a simple question.
I have a load of 7 segmnent displays i got from Aliexpress. Some weer common anode, some common cathode.
partner helpfully tidied my workbanch and mixed the two batches together.
what is the quickest way to establish if they are common anode vs cathode.
i can just see me trying to set up a circuit and spending hours debugging code or somehtign when actually i've picked the wrong type of display
Thanks in advance for helping a newbie
All you need is a 5V supply, a 1K resistor and a bit of patience
If they have some type of marking, like different part numbers, you only need to figure out one of them.
Don't the displays have part numbers on them? Google their data sheets.
could you elaborate?
turns out i'm an idiot and they do have part numbers on them , sorry for wasting peoples time
The part number was not on the back..but it is there . for anyone who may get some use out of this I have 5161AS which are common cathode and 5161BS which are common cathode
Basically what you do is to apply 5V to each pair of pins via the resistor and note which, if any, segments light until you find a common pin, either 5V or GND that allows all of the other segments to light when the opposite voltage is applied
You could write a sketch to do it but can probably do it manually faster than you could write and test the sketch depending on your programming skills
EDIT : I see that you found the answer
thanks this is useful knowledge to have around
My meter has a diode test function, so I use that to check between different pins.
Even better. I avoided suggesting that, as I do not know whether @ZoeBell has a multimeter but if she is using a 7 segment display she must have at least one current limiting resistor
thanks to all, glad some useful information has come out out of my silliness !
I do have a multimeter
Then the cunningly named diode test function is the way to go should you need to
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